Behavior of Square Footing Erected on Gypseous Soil Treated by Ceramic Wastes

Abstract

Gypseous soil, as is well known, includes a specific quantity of gypsum. Gypsum is a water-soluble salt with a solubility of (2.2-2.6) gram/liter in distilled - water. As a result, the presence of gypsum poses a challenge when building structures on this soil, since gypsum dissolves when exposed to water, producing gaps between soil particles and so causing soil collapse. This study examines the behavior of a shallow foundation rested on gypseous soil. Three types of gypseous soil with gypsum contents of (61%, 45.3%, and 27.9%, respectively) are used, and treated with ceramic wastes, which is a waste product of construction. The Soil samples were collected from the site of Tikrit University's campus. The study consists of six test cases, two for each type of soil, one dry and the other wet, where the first test for each case was used as a baseline for comparison, which was the soil test without the addition of ceramic wastes, and the rest was added in three proportions (3%, 6%, and 9%) and three mixing depths for each ratio (B/2, B, 3B/2).The percentage 9% ceramic wastes gives best results of improving, the bearing capacity of the soil improved by 233%, 256 %, and 289% for high gypseous soil, and by 78%, 94%, and 111% for medium gypseous soil, with a percentage of 60%, 87%, and 113% for low gypseous soils. Adding ceramic wastes to wet gypseous soil improves the bearing strength of the soil, lowers settlement to some extent, and reduces the influence of water on it.